U.S. patent number 10,704,458 [Application Number 16/115,413] was granted by the patent office on 2020-07-07 for methods and systems for a turbocharger.
This patent grant is currently assigned to Ford Global Technologies, LLC. The grantee listed for this patent is Ford Global Technologies, LLC. Invention is credited to Guenter Grosch, Andreas Kuske, Rainer Lach, Franz A. Sommerhoff.
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United States Patent |
10,704,458 |
Grosch , et al. |
July 7, 2020 |
Methods and systems for a turbocharger
Abstract
Methods and systems are provided for a compressor of an
exhaust-gas turbocharger. In one example, a system may include
where a housing of the compressor comprises two outlets, a first
outlet shaped to direct compressed air to an electrically driveable
compressor and a second outlet shaped to bypass compressed air
around the electrically driveable compressor.
Inventors: |
Grosch; Guenter (Vettweiss,
DE), Kuske; Andreas (Geulle, NL),
Sommerhoff; Franz A. (Aachen, DE), Lach; Rainer
(Wuerselen, DE) |
Applicant: |
Name |
City |
State |
Country |
Type |
Ford Global Technologies, LLC |
Dearborn |
MI |
US |
|
|
Assignee: |
Ford Global Technologies, LLC
(Dearborn, MI)
|
Family
ID: |
65639067 |
Appl.
No.: |
16/115,413 |
Filed: |
August 28, 2018 |
Prior Publication Data
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|
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Document
Identifier |
Publication Date |
|
US 20190107044 A1 |
Apr 11, 2019 |
|
Foreign Application Priority Data
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|
|
|
|
Oct 6, 2017 [DE] |
|
|
10 2017 217 759 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F02B
37/14 (20130101); F02B 37/164 (20130101); F02B
39/10 (20130101); F02B 37/04 (20130101); F02D
41/0007 (20130101); Y02T 10/12 (20130101) |
Current International
Class: |
F02B
37/04 (20060101); F02B 37/14 (20060101); F02D
41/00 (20060101); F02B 39/10 (20060101); F02B
37/16 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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10019774 |
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Nov 2001 |
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DE |
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10038244 |
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Mar 2002 |
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DE |
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10261790 |
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Jul 2004 |
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DE |
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102007055507 |
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Jun 2009 |
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DE |
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102010027220 |
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Jan 2012 |
|
DE |
|
3133289 |
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Feb 2017 |
|
EP |
|
2009065394 |
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May 2009 |
|
WO |
|
Primary Examiner: Bogue; Jesse S
Attorney, Agent or Firm: Brumbaugh; Geoffrey McCoy Russell
LLP
Claims
The invention claimed is:
1. A supercharged internal combustion engine comprising: an intake
system shaped to supply charge air; an exhaust-gas discharge system
shaped to discharge exhaust gas; at least one exhaust-gas
turbocharger which comprises a turbine arranged in the exhaust-gas
discharge system and a compressor arranged in the intake system,
the compressor being equipped with at least one impeller which is
arranged on a rotatable shaft in a compressor housing, the
compressor housing having a charge-air-conducting flow duct which
extends from an inlet region of the compressor and extends
downstream of the at least one impeller; and an electrically
driveable compressor, which is arranged in the intake system
downstream of the compressor of the at least one exhaust-gas
turbocharger, wherein the compressor housing has at least two
outlets, the charge-air-conducting flow duct splitting downstream
of the at least one impeller into at least two arm-like duct
branches, where at least one shut-off element is arranged at a
junction of the at least two arm-like duct branches including a
first arm-like duct fluidly coupled to a first outlet and a second
arm-like duct fluidly coupled to a second outlet, the first outlet
directing compressed air from the compressor of the at least one
exhaust-gas turbocharger to the electrically driveable compressor
and the second outlet to a bypass passage bypassing the
electrically drivable compressor, wherein the at least one shut-off
element is adjustable via controller in a first mode to block only
the compressed air to the electrically drivable compressor and in a
second mode to block only the bypass passage.
2. The supercharged internal combustion engine of claim 1, wherein
the at least one shut-off element is a single shut-off element
arranged at the junction and adjustable to direct the compressed
air flow to only one of the first or second arm-like duct
branches.
3. The supercharged internal combustion engine of claim 1, wherein
the first arm-like duct branch comprises a first shut-off element
arranged at the junction and where the second arm-like duct branch
comprises a second shut-off element arranged at the junction, and
wherein the first and second shut-off elements are adjustable to
prevent flow through each of the first and second arm-like duct
branches.
4. The supercharged internal combustion engine of claim 1, further
comprising an intercooler arranged between the compressor of the at
least one exhaust-gas turbocharger, wherein compressed air flowing
through the bypass passage does not travel through the
intercooler.
5. A system comprising: a compressor of an exhaust-gas turbocharger
comprising a compressor housing having a plurality of outlets
including a first outlet and a second outlet, and where at least
one shut off-element is arranged at a junction of a first duct
leading to the first outlet and a second duct leading to the second
outlet, wherein the first outlet directs compressed air from the
compressor to an electrically driveable compressor and the second
outlet directs compressed air through a bypass passage to bypass
the electrically driveable compressor, wherein the at least one
shut-off element is adjustable via controller in a first mode to
block only the compressed air to the electrically drivable
compressor and in a second mode to block only the bypass
passage.
6. The system of claim 5, further comprising a controller with
computer-readable instructions stored on non-transitory memory
thereof that, when executed, enable the controller to adjust the at
least one shut-off element to adjust compressed air flow to the
first outlet to increase compressed air flow to the electrically
driveable compressor in response to an amount of boost provided by
the compressor of the exhaust-gas turbocharger being less than an
amount of boost desired.
7. The system of claim 6, wherein the controller further comprises
instructions enabling the controller to adjust the at least one
shut-off element to decrease the compressed air flow to the
electrically driveable compressor in response to the amount of
boost provided by the compressor of the exhaust-gas turbocharger
being equal to the amount of boost desired.
8. The system of claim 5, wherein the compressor of the exhaust-gas
turbocharger is larger than the electrically driveable
compressor.
9. The system of claim 5, wherein the first outlet is separated
from the second outlet, and wherein compressed air flowing through
one of the first or second duct does not mix with compressed air in
the other of the first or second duct.
10. The system of claim 5, wherein the compressor of the
exhaust-gas turbocharger is arranged along a single intake passage,
and wherein the electrically driveable compressor and the bypass
passage are arranged downstream of the junction of the compressor
housing.
11. The system of claim 10, further comprising an intercooler
arranged between the compressor of the exhaust-gas turbocharger and
the electrically driveable compressor, wherein only compressed air
flowing through the first outlet flows through the intercooler.
12. The system of claim 10, further comprising a charge-air cooler
arranged in the single intake passage downstream of each of the
electrically driveable compressor and the bypass passage, wherein
compressed air flowing out of each of the electrically driveable
compressor and the bypass passage flows to the charge-air
cooler.
13. A method comprising: flowing charge-air to a compressor of an
exhaust-gas turbocharger to provide an amount of boost in response
to a boost demand; adjusting via controller a shut-off element
arranged at a junction of a first duct and a second duct of a
housing of the compressor to flow air compressed by the compressor
through the first duct to a first outlet arranged in the housing
and seal the second duct with the shut-off element in response to
the amount of boost being less than an amount of boost demanded,
wherein the first outlet directs the compressed air to a passage to
an electrically driveable compressor; and adjusting via the
controller the shut-off element to flow air compressed by the
compressor through the second duct to a second outlet arranged in
the housing and seal the first duct with the shut-off element in
response to the amount of boost being equal to the amount of boost
demanded, wherein the second outlet directs the compressed air to a
bypass passage which bypasses the electrically driveable
compressor.
14. The method of claim 13, wherein adjusting the shut-off element
to flow the compressed air to the electrically driveable compressor
further includes activating an electric motor to spin the
electrically driveable compressor.
15. The method of claim 13, wherein the first outlet and the second
outlet are adjacent to each other and the bypass passage and the
passage to the electrically driveable compressor only connect
downstream of the electrically driveable compressor.
16. The method of claim 13, wherein the housing comprises no
additional inlets or other outlets other than an exhaust-gas
turbocharger inlet, the first outlet, and the second outlet.
17. The method of claim 13, wherein compressed air flowing through
the first or second duct does not flow into or mix with air in the
other of the first or second duct.
18. The method of claim 13, wherein flowing compressed air through
the first outlet further includes flowing the compressed air
through an intercooler before flowing the compressed air to the
electrically driveable compressor.
19. The method of claim 13, wherein the shut-off element is a
pivotable flap adjustable to seal off each of the first duct and
the second duct.
20. The method of claim 13, further comprising adjusting the
shut-off element to flow compressed air to a third duct connected
to an intercooler.
Description
CROSS REFERENCE TO RELATED APPLICATION
This application claims priority to German Patent Application No.
102017217759.4, filed Oct. 6, 2017. The entire contents of the
above-referenced application are hereby incorporated by reference
in its entirety for all purposes.
FIELD
The present disclosure relates generally to an engine comprising a
turbocharger comprising a compressor shaped to be at least
partially driven by an electric motor.
BACKGROUND/SUMMARY
Internal combustion engines may be equipped with a supercharging
arrangement, wherein supercharging may provide a method for
increasing power, in which the charge air used for the combustion
process in the engine is compressed, as a result of which a greater
mass of charge air can be supplied to each cylinder per working
cycle. In this way, the fuel mass and therefore the mean pressure
can be increased.
Supercharging is a suitable method for increasing the power of an
internal combustion engine while maintaining an unchanged swept
volume, or for reducing the swept volume while maintaining the same
power. In many cases, supercharging leads to an increase in
volumetric power output and a more expedient power-to-weight ratio.
If the swept volume is reduced, it is possible, given the same
vehicle boundary conditions, to shift the load collective toward
higher loads, at which the specific fuel consumption is lower.
Supercharging of an internal combustion engine consequently assists
may increase engine efficiency and decrease fuel consumption.
Some transmission configurations may provide downspeeding, whereby
a lower specific fuel consumption is likewise achieved. In the case
of downspeeding, use is made of the fact that a specific fuel
consumption at low engine speeds is generally lower, in particular
in the presence of relatively high loads.
Supercharging may be provided via an exhaust-gas turbocharger, in
which a compressor and a turbine are arranged on the same shaft.
The hot exhaust-gas flow may be fed to and expand in the turbine
with a release of energy, as a result of which the shaft is set in
rotation. The energy supplied by the exhaust-gas flow to the shaft
is used for driving the compressor which is likewise arranged on
the shaft. The compressor delivers and compresses the charge air
supplied to it, as a result of which supercharging of the at least
one cylinder is obtained. A charge-air cooler may be provided in
the intake system downstream of the compressor, wherein the
charge-air cooler may cool the compressed air before directed the
compressed air to one or more engine cylinders. The cooler lowers
the temperature and thereby increases the density of the charge
air, such that the cooler also contributes to improved charging of
the cylinders, that is to say to a greater air mass. In effect,
compression by cooling occurs.
A difference of an exhaust-gas turbocharger in relation to a
supercharger, wherein the supercharger utilizes an auxiliary device
to drive the compressor, may include that an exhaust-gas
turbocharger utilizes the exhaust-gas energy of the hot exhaust
gases, whereas a supercharger draws the energy used for driving it
directly or indirectly from the internal combustion engine and thus
adversely affects, that is to say reduces, the efficiency, at least
for as long as the drive energy does not originate from an energy
recovery source.
If the supercharger is not one that can be driven by means of an
electric machine, that is to say electrically, a mechanical or
kinematic connection for power transmission may be arranged between
the supercharger and the internal combustion engine.
The advantage of a supercharger in relation to an exhaust-gas
turbocharger consists in that the supercharger can generate, and
make available, a desired charge pressure at a greater range of
engine operating conditions. That is to say, the supercharger may
provide a desired charge pressure regardless of the operating state
of the internal combustion engine, in particular regardless of the
present rotational speed of the crankshaft. This applies in
particular to a supercharger which can be driven electrically via
an electric machine.
In previous examples, it is specifically the case that difficulties
may be encountered in achieving an increase in power in some engine
speed ranges via exhaust-gas turbocharging. A torque drop may
observed in the event of a certain engine speed being undershot.
Said torque drop is understandable if one takes into consideration
that the charge pressure ratio is dependent on the turbine pressure
ratio. If the engine speed is reduced, this leads to a smaller
exhaust-gas mass flow and therefore to a lower turbine pressure
ratio. Consequently, toward lower engine speeds, the charge
pressure ratio may likewise decrease. This may result in a torque
drop. It can be sought, using a variety of measures, to improve the
torque characteristic of a supercharged internal combustion
engine.
The internal combustion engine to which the present disclosure
relates has at least one exhaust-gas turbocharger and an
electrically driveable compressor.
The electrically driveable compressor is in this case shaped as an
activatable compressor which is activated when desired to assist an
exhaust-gas turbocharger in compressing the charge air. In the
context of the present disclosure, provision is not made for using
the electrically driveable compressor instead of the exhaust-gas
turbocharging arrangement to generate the charge pressure.
According to the disclosure, the electric drive compressor is
arranged in the intake system downstream of the compressor of the
at least one exhaust-gas turbocharger, and, in the context of a
multi-stage compression or supercharging configuration, compresses
charge error that has already been pre-compressed. That is to say,
the exhaust-gas turbocharger may compress charge-air before the
electrically driveable compressor.
According to some examples, for the purposes of bypassing the
electrically driveable compressor, a bypass line may branch off
from the intake system, with the formation of a first junction,
between the electrically driveable compressor and the compressor of
the at least one exhaust-gas turbocharger and which opens into the
intake system, with the formation of a second junction, downstream
of the electrically driveable compressor and in which a shut-off
element is arranged.
In this way, the line system on the inlet side of the internal
combustion engine, that is to say the intake system, is more
complex than if bypassing lines were omitted. If the lines of the
intake system are shortened, a line system is obtained which has
small radii of curvature, at which the charge-air flow may be
intensely deflected several times, possibly resulting in pressure
losses in the charge-air flow, which may be disadvantageous and
correspond to parasitic power losses. By contrast, a line system
with less frequent and less intense diversion of the charge-air
flow results in an intake system of relatively large volume, which
comprises a sizing equal to a desired size for optimal efficiency
and thus opposes the densest possible packaging of the drive unit
in the engine bay of the vehicle.
The configuration of the intake system generally becomes more
complex if an exhaust-gas recirculation arrangement is provided for
recirculating exhaust gases from the outlet side to the inlet
side.
The inventors have found a solution to at least partially solve the
problems described above associated with exhaust-gas turbochargers
and electrically driven compressors. In one example, the problems
are at least partially solved by a supercharged internal combustion
engine that comprises an intake system for the supply of charge
air, an exhaust-gas discharge system for the discharge of exhaust
gas, at least one exhaust-gas turbocharger which comprises a
turbine arranged in the exhaust-gas discharge system and a
compressor arranged in the intake system, the compressor being
equipped with at least one impeller which is arranged on a
rotatable shaft in a compressor housing, and the compressor housing
having a charge-air-conducting flow duct which proceeds from an
inlet region of the compressor and extends as far as downstream of
the at least one impeller, and an electrically driveable
compressor, which is arranged in the intake system downstream of
the compressor of the at least one exhaust-gas turbocharger,
wherein the compressor housing for the compressor of the
exhaust-gas turbocharger has at least two outlet regions, the
charge-air-conducting flow duct splitting downstream of the at
least one impeller into at least two arm-like duct branches, and in
each case one arm-like duct branch opening into an outlet region, a
first outlet region being connected via the intake system to the
electrically driveable compressor, and the second outlet region
being connected via the intake system, bypassing the electrically
driveable compressor, to the intake system downstream of the
electrically driveable compressor.
It should be understood that the summary above is provided to
introduce in simplified form a selection of concepts that are
further described in the detailed description. It is not meant to
identify key or essential features of the claimed subject matter,
the scope of which is defined uniquely by the claims that follow
the detailed description. Furthermore, the claimed subject matter
is not limited to implementations that solve any disadvantages
noted above or in any part of this disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an engine arranged in a hybrid vehicle.
FIG. 2A shows a first embodiment of a housing of a compressor of an
exhaust gas turbocharger.
FIG. 2B shows a second embodiment of the housing of the compressor
of the exhaust gas turbocharger
FIG. 3 shows an optional arrangement of the exhaust-gas
turbocharger and an electrically driven compressor in an intake
system, which may be used with the engine of FIG. 1.
FIG. 4 shows a method for adjusting compressed air flow to the
electrically driveable compressor.
DETAILED DESCRIPTION
The following description relates to systems and methods for
utilizing one or more compressors for providing boost.
Additionally, the description further describes a shape of a
compressor housing for a compressor of an exhaust-gas turbocharger,
wherein the shape of the compressor housing reduces packaging
constraints. More specifically, the compressor housing may comprise
at least two outlets, wherein a first outlet may direct compressed
air to the electrically driveable compressor and a second outlet
may direct compressed air around the electrically driveable
compressor to a bypass. The compressors may be arranged upstream of
an engine arranged in a hybrid vehicle, as shown in FIG. 1. The
compressor may comprise a plurality of shut-off elements for
adjusting compressed air flow through each of its outlets, as shown
in FIG. 2A. Additionally or alternatively, the compressor may
comprise a single shut-off element for adjusting compressed air
flow through each of its outlets, as shown in FIG. 2B. An example
arrangement of the compressor of the exhaust-gas turbocharger and
the electrically driveable compressor is shown in FIG. 3.
A method for meeting a boost demand with one or more of the
compressor of the exhaust-gas turbocharger and the electrically
driveable compressor is shown in FIG. 4. In some examples, to
preserve a battery state of charge and increase fuel economy, the
electrically driveable compressor may be activated during engine
conditions where the compressor of the exhaust-gas turbocharger may
not be able to meet the boost demand independently.
FIGS. 1-3 show example configurations with relative positioning of
the various components. If shown directly contacting each other, or
directly coupled, then such elements may be referred to as directly
contacting or directly coupled, respectively, at least in one
example. Similarly, elements shown contiguous or adjacent to one
another may be contiguous or adjacent to each other, respectively,
at least in one example. As an example, components laying in
face-sharing contact with each other may be referred to as in
face-sharing contact. As another example, elements positioned apart
from each other with only a space there-between and no other
components may be referred to as such, in at least one example. As
yet another example, elements shown above/below one another, at
opposite sides to one another, or to the left/right of one another
may be referred to as such, relative to one another. Further, as
shown in the figures, a topmost element or point of element may be
referred to as a "top" of the component and a bottommost element or
point of the element may be referred to as a "bottom" of the
component, in at least one example. As used herein, top/bottom,
upper/lower, above/below, may be relative to a vertical axis of the
figures and used to describe positioning of elements of the figures
relative to one another. As such, elements shown above other
elements are positioned vertically above the other elements, in one
example. As yet another example, shapes of the elements depicted
within the figures may be referred to as having those shapes (e.g.,
such as being circular, straight, planar, curved, rounded,
chamfered, angled, or the like). Further, elements shown
intersecting one another may be referred to as intersecting
elements or intersecting one another, in at least one example.
Further still, an element shown within another element or shown
outside of another element may be referred as such, in one example.
It will be appreciated that one or more components referred to as
being "substantially similar and/or identical" differ from one
another according to manufacturing tolerances (e.g., within 1-5%
deviation).
In the case of the internal combustion engine according to the
disclosure, the intake system in the form of the
charge-air-conducting flow duct branches already in the compressor
housing, specifically downstream of the at least one impeller. For
this purpose, the compressor housing according to the disclosure
has at least two ports downstream of the at least one impeller; the
so-called outlet regions.
The charge air enters the compressor housing via the inlet region,
is compressed as it flows through the at least one impeller, and
exits the housing either via a first arm-like duct branch and a
first outlet region or via a second arm-like duct branch and a
second outlet region. The first arm-like duct branch conducts the
pre-compressed charge air via the intake system to the electrically
driveable compressor. The second duct branch conducts the
compressed charge air via the intake system into the intake system
downstream of the electrically driveable compressor, whereby the
electrically driveable compressor is bypassed.
The arrangement of the compressor housing according to the
disclosure has multiple advantageous effects.
A conventional bypass line, which branches off from the intake
system, with the formation of a first junction, between the
electrically driveable compressor and the compressor of the at
least one exhaust-gas turbocharger and which opens into the intake
system, with the formation of a second junction, downstream of the
electrically driveable compressor and in which a shut-off element
is arranged, is omitted. The bypassing of the electrically
driveable compressor is realized using the second duct branch or
the second outlet region. A shut-off element provided in the
housing can serve for opening up and shutting off the second duct
branch, that is to say for activating and deactivating said second
duct branch.
As a result of the branching of the intake system in the compressor
housing, the inlet-side line system of the internal combustion
engine, that is to say the intake system, is made less luminous,
whereby a packaging constraint is correspondingly reduced. Dense
packaging is thus assisted, and the weight of the inlet-side line
system is likewise reduced. The pressure losses in the charge-air
flow can be reduced. As a result of the omission of a conventional
bypass line together with bypass valve, the total length of the
inlet-sidelines of the intake system is also shortened, whereby the
response behavior of the supercharging arrangement may be
increased. That is to say, there may be fewer pipes and/or tubes
for the compressed air to fill, which may increase power output and
efficiency. Furthermore, a manufacturing cost for the intake system
are reduced, specifically inter alia as a result of a reduced use
of material for the lines and reduced assembly effort during the
manufacturing process.
With the internal combustion engine according to the disclosure, a
supercharged internal combustion engine is provided which exhibits
improved packaging and is less expensive.
A compressor housing according to the disclosure may also have,
downstream of the at least one impeller, three or more ports or
outlet regions, for example a third port, that is to say a third
outlet region, which connects the compressed charge air to the
cylinders of the internal combustion engine, bypassing the
electrically driveable compressor and bypassing a charge-air
cooling arrangement provided in the intake system. The latter may
be desired for example during a warm-up phase after a cold
start.
Embodiments of the supercharged internal combustion engine may
comprise where the compressor housing has two outlet regions, the
charge-air-conducting flow duct splitting downstream of the at
least one impeller into two arm-like duct branches, with a junction
being formed, and a first arm-like duct branch opening into the
first outlet region and a second arm-like duct branch opening into
the second outlet region.
Embodiments of the supercharged internal combustion engine may
comprise where each arm-like duct branch may be equipped with a
shut-off element, the respective shut-off element serving for
opening up and shutting off the associated duct branch.
If the compressor housing has two outlet regions, embodiments of
the supercharged internal combustion engine may also comprise where
a common shut-off element is provided for the two arm-like duct
branches, said common shut-off element opening up the first
arm-like duct branch when said common shut-off element shuts off
the second duct branch, and vice versa.
In this context, embodiments of the supercharged internal
combustion engine may comprise where the common shut-off element is
a pivotable flap arranged at the junction.
Embodiments of the supercharged internal combustion engine may
comprise where an intercooler is arranged in the intake system
between the electrically driveable compressor and the compressor of
the at least one exhaust-gas turbocharger.
The intercooler lowers the air temperature upstream of the inlet of
the electrically driveable compressor, whereby the temperature and
the pressure at the outlet of the electrically driveable compressor
are likewise lowered.
Embodiments of the supercharged internal combustion engine may
comprise where the intake system is equipped with a throttle
element which is arranged downstream of the electrically driveable
compressor and downstream of the compressor of the at least one
exhaust-gas turbocharger.
In the case of an applied-ignition internal combustion engine, that
is to say an Otto-cycle engine, the adjustment of the desired power
may be performed through variation of the charge of the combustion
chamber, that is to say via quantity regulation. By adjusting a
throttle element, for example a throttle flap, provided in the
intake tract, the pressure of the delivered charge air downstream
of the throttle element can be reduced to a greater or lesser
extent. For a constant combustion chamber volume, it is possible in
this way for the air mass, that is to say the quantity, to be set
by means of the pressure of the charge air.
Embodiments of the supercharged internal combustion engine may
comprise where the intake system is equipped with a charge-air
cooler which is arranged downstream of the electrically driveable
compressor and downstream of the compressor of the at least one
exhaust-gas turbocharger.
The charge-air cooler lowers the air temperature and thereby
increases the density of the compressed charge air upstream of the
inlet into the cylinders, as a result of which the cooler also
contributes to improved charging of the combustion chamber with
air, that is to say to a greater air mass.
If, in addition to the charge-air cooler, a throttle element is
also arranged downstream of the electrically driveable compressor
and downstream of the compressor of the at least one exhaust-gas
turbocharger, embodiments of the supercharged internal combustion
engine may comprise where the charge-air cooler is arranged
downstream of the throttle element.
Embodiments of the supercharged internal combustion engine may
comprise where the compressor housing has, in the inlet region, a
flange for fastening purposes.
Embodiments of the supercharged internal combustion engine may
comprise where the electrically driveable compressor is designed to
be smaller than the compressor of the at least one exhaust-gas
turbocharger.
This is advantageous in particular with regard to the function
according to the disclosure of the electrically driveable
compressor, which is designed as an activatable compressor and
which, in the context of a multi-stage compression, compresses
charge air that has already been pre-compressed. Here, the
electrically driveable compressor functions as a high-pressure
stage.
Embodiments of the supercharged internal combustion engine may
comprise where only one exhaust-gas turbocharger is provided. This
reduces the weight and costs of the supercharging arrangement.
It is then generally the case that single-stage supercharging or
compression takes place in defined characteristic map areas of the
internal combustion engine. With regard to friction losses and
overall efficiency, it is more advantageous to use a single
exhaust-gas turbocharger than multiple turbochargers, for which
reason the above embodiment has advantages in terms of
efficiency.
Embodiments may comprise where the compressor of the at least one
exhaust-gas turbocharger is equipped with a variable compressor
geometry. A variable compressor geometry has proven to be
advantageous in particular if only a small exhaust-gas flow rate is
conducted through the turbine because, by adjustment of the guide
blades, the surge limit of the compressor in the compressor
characteristic map can be shifted in the direction of small
compressor flows, and thus the compressor is prevented from
operating beyond the surge limit. The variable compressor geometry
therefore also offers advantages if high exhaust-gas flow rates are
branched off upstream of the turbine and recirculated, in order to
realize high recirculation rates. If the turbine of the at least
one exhaust-gas turbocharger has a variable turbine geometry, the
variable compressor geometry can be adapted continuously to the
turbine geometry.
With targeted configuration of the supercharging, it is possible to
obtain advantages not only with regard to the fuel consumption,
that is to say the efficiency of the internal combustion engine,
but also with regard to exhaust-gas emissions. With suitable
supercharging for example of a diesel engine, the nitrogen oxide
emissions can therefore be reduced without any losses in
efficiency. At the same time, the hydrocarbon emissions can be
positively influenced. The emissions of carbon dioxide, which
correlate directly with fuel consumption, decrease in any case with
falling fuel consumption.
To comply with future limit values for pollutant emissions,
however, further measures are desired. Here, the focus of the
development work is on, inter alia, the reduction of nitrogen oxide
emissions, which are of high relevance in particular in diesel
engines. Exhaust-gas recirculation is expedient here.
The exhaust gas can be extracted from the exhaust-gas discharge
system upstream of the turbine and recirculated via high-pressure
exhaust-gas recirculation. However, in the event of an increase in
the exhaust-gas recirculation rate, the exhaust-gas flow introduced
into the turbine simultaneously decreases. The reduced exhaust-gas
mass flow through the turbine leads to a lower turbine pressure
ratio, as a result of which the charge pressure ratio also falls,
which equates to a smaller compressor mass flow. Aside from the
decreasing charge pressure, problems may additionally arise in the
operation of the compressor with regard to the surge limit.
Disadvantages may also arise in terms of the pollutant emissions,
for example with regard to the formation of soot during an
acceleration in the case of diesel engines.
For this reason, the exhaust gas may also be recirculated by means
of low-pressure EGR. By contrast to the abovementioned
high-pressure EGR arrangement, in which exhaust gas is extracted
from the exhaust-gas discharge system upstream of the turbine and
introduced into the intake system downstream of a compressor, in
the case of a low-pressure EGR arrangement exhaust gas which has
already flowed through the turbine is recirculated to the inlet
side. For this purpose, the low-pressure EGR arrangement comprises
a recirculation line which branches off from the exhaust-gas
discharge system downstream of the turbine and which opens into the
intake system upstream of the compressor.
In some embodiments, additionally or alternatively, a method for
operating a supercharged internal combustion engine in which the
compressor housing has two outlet regions, the
charge-air-conducting flow duct splitting downstream of the at
least one impeller into two arm-like duct branches, with a junction
being formed, and a first arm-like duct branch opening into the
first outlet region and a second arm-like duct branch opening into
the second outlet region, may comprise where the first arm-like
duct branch is opened up and the second arm-like duct branch is
shut off in order to compress the charge air in multi-stage fashion
using the electrically driveable compressor.
Additionally or alternatively, the method may optionally include
where the first arm-like duct branch is shut off and the second
arm-like duct branch is opened up in order to bypass the
electrically driveable compressor in the course of the
supercharging.
An internal combustion engine, such as the engine described above,
is used as a motor vehicle drive unit. Within the context of the
present disclosure, the expression internal combustion engine may
encompass diesel engines and Otto-cycle engines, but also hybrid
internal combustion engines, that is to say internal combustion
engines which are operated with a hybrid combustion process, and
hybrid drives which, in addition to the internal combustion engine,
comprise at least one further torque source for driving the motor
vehicle, for example an electric machine which is connectable in
terms of drive or connected in terms of drive to the internal
combustion engine and which outputs power instead of the internal
combustion engine or in addition to the internal combustion
engine.
FIG. 1 depicts an engine system 100 for a vehicle. The vehicle may
be an on-road vehicle having drive wheels which contact a road
surface. Engine system 100 includes engine 10 which comprises a
plurality of cylinders. FIG. 1 describes one such cylinder or
combustion chamber in detail. The various components of engine 10
may be controlled by electronic engine controller 12.
Engine 10 includes a cylinder block 14 including at least one
cylinder bore 20, and a cylinder head 16 including intake valves
152 and exhaust valves 154. In other examples, the cylinder head 16
may include one or more intake ports and/or exhaust ports in
examples where the engine 10 is configured as a two-stroke engine.
The cylinder block 14 includes cylinder walls 32 with piston 36
positioned therein and connected to crankshaft 40. Thus, when
coupled together, the cylinder head 16 and cylinder block 14 may
form one or more combustion chambers. As such, the combustion
chamber 30 volume is adjusted based on an oscillation of the piston
36. Combustion chamber 30 may also be referred to herein as
cylinder 30. The combustion chamber 30 is shown communicating with
intake manifold 144 and exhaust manifold 148 via respective intake
valves 152 and exhaust valves 154. Each intake and exhaust valve
may be operated by an intake cam 51 and an exhaust cam 53.
Alternatively, one or more of the intake and exhaust valves may be
operated by an electromechanically controlled valve coil and
armature assembly. The position of intake cam 51 may be determined
by intake cam sensor 55. The position of exhaust cam 53 may be
determined by exhaust cam sensor 57. Thus, when the valves 152 and
154 are closed, the combustion chamber 30 and cylinder bore 20 may
be fluidly sealed, such that gases may not enter or leave the
combustion chamber 30.
Combustion chamber 30 may be formed by the cylinder walls 32 of
cylinder block 14, piston 36, and cylinder head 16. Cylinder block
14 may include the cylinder walls 32, piston 36, crankshaft 40,
etc. Cylinder head 16 may include one or more fuel injectors such
as fuel injector 66, one or more intake valves 152, and one or more
exhaust valves such as exhaust valves 154. The cylinder head 16 may
be coupled to the cylinder block 14 via fasteners, such as bolts
and/or screws. In particular, when coupled, the cylinder block 14
and cylinder head 16 may be in sealing contact with one another via
a gasket, and as such the cylinder block 14 and cylinder head 16
may seal the combustion chamber 30, such that gases may only flow
into and/or out of the combustion chamber 30 via intake manifold
144 when intake valves 152 are opened, and/or via exhaust manifold
148 when exhaust valves 154 are opened. In some examples, only one
intake valve and one exhaust valve may be included for each
combustion chamber 30. However, in other examples, more than one
intake valve and/or more than one exhaust valve may be included in
each combustion chamber 30 of engine 10.
In some examples, each cylinder of engine 10 may include a spark
plug 192 for initiating combustion. Ignition system 190 can provide
an ignition spark to cylinder 14 via spark plug 192 in response to
spark advance signal SA from controller 12, under select operating
modes. However, in some embodiments, spark plug 192 may be omitted,
such as where engine 10 may initiate combustion by auto-ignition or
by injection of fuel as may be the case with some diesel
engines.
Fuel injector 66 may be positioned to inject fuel directly into
combustion chamber 30, which is known to those skilled in the art
as direct injection. Fuel injector 66 delivers liquid fuel in
proportion to the pulse width of signal FPW from controller 12.
Fuel is delivered to fuel injector 66 by a fuel system (not shown)
including a fuel tank, fuel pump, and fuel rail. Fuel injector 66
is supplied operating current from driver 68 which responds to
controller 12. In some examples, the engine 10 may be a gasoline
engine, and the fuel tank may include gasoline, which may be
injected by injector 66 into the combustion chamber 30. However, in
other examples, the engine 10 may be a diesel engine, and the fuel
tank may include diesel fuel, which may be injected by injector 66
into the combustion chamber. Further, in such examples where the
engine 10 is configured as a diesel engine, the engine 10 may
include a glow plug to initiate combustion in the combustion
chamber 30.
The injector 66 may be shaped to flow a mixture of liquids and/or
gases through one or more of its passages to be injected into the
combustion chamber 30. The mixture may include one or more of
alcohol, different octane rated fuels, diesel, cleaners, catalysts,
and the like.
Intake manifold 144 is shown communicating with throttle 62 which
adjusts a position of throttle plate 64 to control airflow to
engine cylinder 30. This may include controlling airflow of boosted
air from intake boost chamber 146. In some embodiments, throttle 62
may be omitted and airflow to the engine may be controlled via a
single air intake system throttle (AIS throttle) 82 coupled to air
intake passage 42 and located upstream of the intake boost chamber
146. In yet further examples, AIS throttle 82 may be omitted and
airflow to the engine may be controlled with the throttle 62.
In some embodiments, engine 10 is configured to provide exhaust gas
recirculation, or EGR. When included, EGR may be provided as
high-pressure EGR and/or low-pressure EGR. In examples where the
engine 10 includes low-pressure EGR, the low-pressure EGR may be
provided via EGR passage 135 and EGR valve 138 to the engine air
intake system at a position downstream of air intake system (AIS)
throttle 82 and upstream of compressor 162 from a location in the
exhaust system downstream of turbine 164. EGR may be drawn from the
exhaust system to the intake air system when there is a pressure
differential to drive the flow. A pressure differential can be
created by partially closing AIS throttle 82. Throttle plate 84
controls pressure at the inlet to compressor 162. The AIS may be
electrically controlled and its position may be adjusted based on
optional position sensor 88.
Ambient air is drawn into combustion chamber 30 via intake passage
42, which includes air filter 156. Thus, air first enters the
intake passage 42 through air filter 156. Compressor 162 then draws
air from air intake passage 42 to supply boost chamber 146 with
compressed air via a compressor outlet tube (not shown in FIG. 1).
In some examples, air intake passage 42 may include an air box (not
shown) with a filter. In one example, compressor 162 may be a
turbocharger, where power to the compressor 162 is drawn from the
flow of exhaust gases through turbine 164. Specifically, exhaust
gases may spin turbine 164 which is coupled to compressor 162 via
shaft 161. A wastegate 72 allows exhaust gases to bypass turbine
164 so that boost pressure can be controlled under varying
operating conditions. Wastegate 72 may be closed (or an opening of
the wastegate may be decreased) in response to increased boost
demand, such as during an operator pedal tip-in. By closing the
wastegate, exhaust pressures upstream of the turbine can be
increased, raising turbine speed and peak power output. This allows
boost pressure to be raised. Additionally, the wastegate can be
moved toward the closed position to maintain desired boost pressure
when the compressor recirculation valve is partially open. In
another example, wastegate 72 may be opened (or an opening of the
wastegate may be increased) in response to decreased boost demand,
such as during an operator pedal tip-out. By opening the wastegate,
exhaust pressures can be reduced, reducing turbine speed and
turbine power. This allows boost pressure to be lowered.
However, in alternate embodiments, the compressor 162 may be a
supercharger, where power to the compressor 162 is drawn from the
crankshaft 40. Thus, the compressor 162 may be coupled to the
crankshaft 40 via a mechanical linkage such as a belt. As such, a
portion of the rotational energy output by the crankshaft 40, may
be transferred to the compressor 162 for powering the compressor
162.
An electrically driveable compressor 166 may be arranged downstream
of the compressor 162 in the intake boost chamber 146. As shown,
the compressor 162 may comprise at least two outlets, a first
outlet leading to the electrically driveable compressor 166 and the
second outlet bypassing the electrically driveable compressor 166.
Thus, the intake boost chamber 146 may be divided into at least two
portions via partition 167, while maintaining a same relative
volume as previous examples, thereby reducing pressure losses which
may be incurred due to compressed air entering volumes of pipes
forming auxiliary passages. As will be described in greater detail
below, the compressor housing of the compressor 162 of the
exhaust-gas turbocharger may be shaped to decrease a volume of
materials used to arrange the intake system of engine 10 in such a
way that pressure losses resulting from compressed gas filling
piping for directing air to a bypass, charge-air cooler,
electrically driveable compressor, or the like are mitigated and/or
prevented. This may result in increased fuel economy and increased
power output.
Universal Exhaust Gas Oxygen (UEGO) sensor 126 is shown coupled to
exhaust manifold 148 upstream of emission control device 70.
Alternatively, a two-state exhaust gas oxygen sensor may be
substituted for UEGO sensor 126. Emission control device 70 may
include multiple catalyst bricks, in one example. In another
example, multiple emission control devices, each with multiple
bricks, can be used. While the depicted example shows UEGO sensor
126 upstream of turbine 164, it will be appreciated that in
alternate embodiments, UEGO sensor may be positioned in the exhaust
manifold downstream of turbine 164 and upstream of emission control
device 70. Additionally or alternatively, the emission control
device 70 may comprise a diesel oxidation catalyst (DOC) and/or a
diesel cold-start catalyst, a particulate filter, a three-way
catalyst, a NO.sub.x trap, selective catalytic reduction device,
and combinations thereof. In some examples, a sensor may be
arranged upstream or downstream of the emission control device 70,
wherein the sensor may be configured to diagnose a condition of the
emission control device 70.
Controller 12 is shown in FIG. 1 as a microcomputer including:
microprocessor unit 102, input/output ports 104, read-only memory
106, random access memory 108, keep alive memory 110, and a
conventional data bus. Controller 12 is shown receiving various
signals from sensors coupled to engine 10, in addition to those
signals previously discussed, including: engine coolant temperature
(ECT) from temperature sensor 112 coupled to cooling sleeve 114; a
position sensor 134 coupled to an input device 130 for sensing
input device pedal position (PP) adjusted by a vehicle operator
132; a knock sensor for determining ignition of end gases (not
shown); a measurement of engine manifold pressure (MAP) from
pressure sensor 121 coupled to intake manifold 144; a measurement
of boost pressure from pressure sensor 122 coupled to boost chamber
146; an engine position sensor from a Hall effect sensor 118
sensing crankshaft 40 position; a measurement of air mass entering
the engine from sensor 120 (e.g., a hot wire air flow meter); and a
measurement of throttle position from sensor 58. Barometric
pressure may also be sensed (sensor not shown) for processing by
controller 12. In a preferred aspect of the present description,
Hall effect sensor 118 produces a predetermined number of equally
spaced pulses every revolution of the crankshaft from which engine
speed (RPM) can be determined. The input device 130 may comprise an
accelerator pedal and/or a brake pedal. As such, output from the
position sensor 134 may be used to determine the position of the
accelerator pedal and/or brake pedal of the input device 130, and
therefore determine a desired engine torque. Thus, a desired engine
torque as requested by the vehicle operator 132 may be estimated
based on the pedal position of the input device 130.
In some examples, vehicle 5 may be a hybrid vehicle with multiple
sources of torque available to one or more vehicle wheels 59. In
other examples, vehicle 5 is a conventional vehicle with only an
engine, or an electric vehicle with only electric machine(s). In
the example shown, vehicle 5 includes engine 10 and an electric
machine 52. Electric machine 52 may be a motor or a
motor/generator. Crankshaft 40 of engine 10 and electric machine 52
are connected via a transmission 54 to vehicle wheels 59 when one
or more clutches 56 are engaged. In the depicted example, a first
clutch 56 is provided between crankshaft 40 and electric machine
52, and a second clutch 56 is provided between electric machine 52
and transmission 54. Controller 12 may send a signal to an actuator
of each clutch 56 to engage or disengage the clutch, so as to
connect or disconnect crankshaft 40 from electric machine 52 and
the components connected thereto, and/or connect or disconnect
electric machine 52 from transmission 54 and the components
connected thereto. Transmission 54 may be a gearbox, a planetary
gear system, or another type of transmission. The powertrain may be
configured in various manners including as a parallel, a series, or
a series-parallel hybrid vehicle.
Electric machine 52 receives electrical power from a traction
battery 58 to provide torque to vehicle wheels 59. Electric machine
52 may also be operated as a generator to provide electrical power
to charge battery 58, for example during a braking operation.
The controller 12 receives signals from the various sensors of FIG.
1 and employs the various actuators of FIG. 1 to adjust engine
operation based on the received signals and instructions stored on
a memory of the controller. For example, adjusting operation of the
fuel injector 66 may include signaling to an actuator of the
injector to inject more or less fuel.
Turning now to FIG. 2A, it schematically shows an embodiment 200 of
the compressor 162 arranged in an exhaust-gas turbocharger. The
exhaust-gas turbocharger may further include the turbine 164 of
FIG. 1. As such, components previously introduced may be similarly
numbered in subsequent figures. As described above, the turbine and
compressor 162 may be arranged on a shared shaft (shaft 161 of FIG.
1), wherein exhaust gas may flow through the turbine, and the shaft
may transfer the energy imparted from the exhaust gas to the
turbine to the compressor 162, which may compress charge air.
More specifically, the hot exhaust gas may expand in the turbine
with a release of energy, and drive the compressor 162 via rotation
of the shaft. The compressor 162 compresses the charge air which is
supplied to the cylinders via an intake boost chamber (e.g. intake
boost chamber 146 of FIG. 1), as a result of which the
supercharging of the internal combustion engine is realized.
The compressor 162 may be equipped with an impeller 212 arranged on
a rotatable shaft, which impeller is arranged in a compressor
housing 214. The compressor housing 214 may comprise a
charge-air-conducting flow duct 216 which proceeds from an inlet
region 218 of the compressor 162 and extends downstream of the
impeller 212.
The compressor housing 214 may comprise a plurality of outlets 220
including a first outlet 222 and a second outlet 224. The
charge-air-conducting flow duct 216 may divide downstream of the
impeller 212, upstream of the plurality of outlets 220, forming a
first arm-like duct branch 232 and a second arm-like duct branch
234. A junction 236 may be formed between the first and second
arm-like duct branches 232, 234. Each of the first and second
arm-like duct branches 232, 234 may be fluidly coupled to one
outlet of the plurality of outlets 220. In the example of FIG. 2A,
the first arm-like duct branch 232 is fluidly coupled to the first
outlet 222 and the second arm-like duct branch 234 is fluidly
coupled to the second outlet 224. Compressed air in the first
arm-like duct branch 232 may not flow to the second outlet 224 or
mix with compressed air in the second arm-like duct branch 234.
Similarly, compressed air in the second arm-like duct branch 234
may not flow to the first outlet 222 or mix with compressed air in
the first arm-like duct branch 232.
The first outlet 222 is connected via the intake boost chamber to
an electrically driveable compressor, such as the electrically
driveable compressor 166 of FIG. 1. The second outlet 224 may be
fluidly coupled to a portion of intake passage 42 which is sealed
from the electrically driveable compressor 166. As such, compressed
air in the second outlet 224 may bypass the electrically driveable
compressor, to the engine downstream of the electrically driveable
compressor (e.g., engine 10 of FIG. 1).
Each of the first and second arm-like duct branches 232, 234 may be
equipped with a dedicated shut-off element 242, 244, the respective
shut-off elements 242, 244 serving for opening up and shutting off
the associated duct branch 232, 234. More specifically, the first
arm-like duct branch 232 may comprise a first shut-off element 242
and the second arm-like duct branch 234 may comprise a second
shut-off element 244. Each of the first and second shut-off
elements 242, 244 may be a butterfly valve. However, it will be
appreciated that other flow adjusting devices may be used without
departing from the scope of the present disclosure.
Turning now to FIG. 2B, it schematically shows an embodiment 250 of
the compressor 162 of an exhaust-gas turbocharger. The embodiment
250 of the exhaust-gas turbocharger may be substantially similar to
the embodiment 200 of FIG. 2A. More specifically, the embodiment
250 differs from the embodiment 200 in that the embodiment 250
comprises a single shut-off element 252 arranged at the junction
236 between the first and second arm-like ducts 232, 234.
The single shut-off element 252 may be a flap or the like, wherein
the single shut-off element may be shaped to adjust compressed air
flow to each of the first and second arm-like ducts 232, 234. As
such, when the single shut-off element 252 is actuated to a
position fully sealing one of the arm-like ducts, then the other
arm-like duct may receive a maximum amount of compressed air for a
given compressor 162 speed. For example, if the single shut-off
element 252 is actuated to a position to fully close the first
arm-like duct 232 (such as the position shown by solid line 252A),
then all the compressed air produced by the compressor 162 of the
exhaust-gas turbocharger may flow to the second arm-like duct 234,
thereby bypassing the electrically driveable compressor. As another
example, if the single shut-off element 252 is actuated to a
position to fully closed the second arm-like duct 234 (such as the
position show by dashed line 252B), then all the compressed air
produced by the compressor 162 of the exhaust gas turbocharger may
flow to the first arm-like duct 232, thereby flowing the compressed
air to the electrically driveable compressor for further
compression.
In some examples, the compressor of the exhaust-gas turbocharger
may comprise more than two outlets. In one example, the compressor
may comprise three outlets, wherein the first outlet directs
compressed air to the electrically driveable compressor, the second
outlet directs compressed air to the bypass, and a third outlet
directs compressed air to a charge-air cooler. As such, compressed
air flowing to the charge-air cooler may not flow to the
electrically driveable compressor while still increasing boost
pressure via compression by cooling. Relative to the example of
FIG. 1, the charge-air cooler may be arranged adjacent to the
electrically driveable compressor 166 and the bypass passage, such
that packaging restraints are decreased and pressure losses due to
extra piping used in previous examples to conduct compressed air
flow to desired locations is also decreased.
Turning now to FIG. 3, it schematically shows an embodiment 300 of
an intake system 301 of the embodiments 200 or 250 of FIGS. 2A and
2B, respectively.
The compressor housing (e.g., compressor housing 214 of FIGS. 2A
and 2B) of the compressor 162 arranged in the intake system 301
comprises first and second outlets 222, 224, the first outlet 222
being connected via the intake system 301 to the electrically
driveable compressor 166, and the second outlet region 224 being
connected, bypassing the electrically driveable compressor 166, to
a portion of the intake system 1 downstream of the electrically
driveable compressor 7.
In the example of FIG. 3, an intercooler 310 is arranged in the
intake system 301 between the electrically driveable compressor 166
and the compressor 162 of the exhaust-gas turbocharger. The
intercooler 310 may lower the temperature of the pre-compressed
charge air upstream of the inlet into the electrically driveable
compressor 166, whereby the temperature and the pressure at the
outlet of the electrically driveable compressor 166 are also
lowered, and the electrically driveable compressor 166 is protected
against damage resulting from thermal overloading.
Furthermore, the intake system 301 is equipped with a throttle 62
which is arranged downstream of the electrically driveable
compressor 166 and downstream of the compressor 162 of the
exhaust-gas turbocharger. By adjusting the throttle 62, the
charge-air quantity supplied to cylinders 312 can be adjusted,
wherein cylinders 312 may include combustion chamber 30 of FIG.
1.
Furthermore, a charge-air cooler 309 may be arranged downstream of
the throttle 62. The charge-air cooler 309 may lower the air
temperature and thereby increase the density of the compressed
charge air upstream of the inlet into the cylinders 312, as a
result of which said cooler 309 also contributes to increase
charging of the cylinders 312.
As described above, the compressor housing may be shaped
differently to provide a desired number of outlets corresponding to
a desired number of flow paths, wherein each of the flow paths may
be fluidly sealed from one another. Additionally or alternatively,
one or more of the charge-air cooler 309 and/or the intercooler 310
may be omitted.
Turning now to FIG. 4, it shows a method 400 for adjusting
compressed air flow to the electrically driveable compressor.
The method 400 begins at 402, which includes determining,
estimating, and/or measuring current engine operating parameters.
Current engine operating parameters may include, but are not
limited to, one or more of manifold pressure, boost, engine speed,
exhaust-gas recirculation flow rate, engine speed, engine
temperature, engine load, compressor speed, and air/fuel ratio.
Boost may be calculated via summing the boost provided by each of
the compressor of the exhaust-gas turbocharger and the electrically
driveable compressor.
The method 400 may proceed to 404 to determine if boost is desired.
In some examples of the method 400, additionally or alternatively,
if boost is already desired, then 404 may include determining if an
amount of boost desired has increased. Boost may be desired during
transient engine operating conditions, such as a pedal tip-in, high
loads, or the like. If boost is not desired, then the method 400
may proceed to 406 to maintain current operating parameters and
does not increase boost to the engine. In some examples, this may
further include, additionally or alternatively, bypassing one or
more of the compressor of the exhaust-gas turbocharger and the
electrically driveable compressor.
If boost is desired, then the method 400 may proceed to 408 to
compress intake air with the compressor of the exhaust-gas
turbocharger. As such, exhaust gases generated via the engine, that
are not rerouted as high-pressure EGR, may spin a turbine and
provide a corresponding amount of boost. As such, boost provided by
the compressor of the exhaust-gas turbocharger may be directly
proportional to an amount of exhaust gas flowing to the
turbine.
The method 400 may proceed to 410 to determine if a boost demand is
met by the compressor of the exhaust-gas turbocharger. If the boost
demand is met by the compressor of the exhaust-gas turbocharger,
then the method 400 may proceed to 412 to maintain current
operating parameters and does not flow or increase compressed air
flow to the electrically driveable compressor. By doing this, fuel
economy may be increased as a battery state of charge may not be
drained to power an electric motor.
In the example of FIG. 2A, this may include maintaining a position
of the each of the first and second shut-off elements 242, 244 so
that amounts of compressed air flowing to the electrically driven
compressor and the bypass remain unchanged. In the example of FIG.
2B, this may include maintaining a position of the single shut-off
element 252 so that amounts of compressed air flowing to the
electrically driven compressor and the bypass remain unchanged.
Returning to 410, if the boost demand is not met by the compressor
of the exhaust-gas turbocharger, then the method 400 may proceed to
414 to flow and/or increase compressed air flow to the electrically
driveable compressor. As such, the compressor of the exhaust-gas
turbocharger may be providing as much compressed air as possible
under current engine operating conditions, which may be
insufficient to completely meet the desired amount of boost. In
this way, the electric motor may be activated to spin the
electrically driven compressor to further compress compressed air
from the compressor of the exhaust-gas turbocharger to meet the
boost demand. While battery state of charge is consumed to operate
the electrically driveable compressor, fuel economy savings
obtained from operating both the compressors may outweigh the
electrical energy consumed while providing a desired power
output.
In the example of FIG. 2A, increasing compressed air flow to the
electrically driveable compressor may include actuating the first
shut-off element 242 to a more open position and actuating the
second shut-off element 244 to a more closed position. In the
example of FIG. 2B, increasing compressed air flow to the
electrically driveable compressor may include actuating the single
shut-off element 252 to a position where the opening of the first
arm-like duct 232 is more open and the opening of the second
arm-like duct 234 is more closed, thereby increasing compressed air
flow to the electrically driveable compressor and decreasing
compressed air flow to the bypass.
The method 400 to 416, which may include continuing to flow
compressed air to the electrically driveable compressor until the
compressor of the exhaust-gas turbocharger can meet the boost
demand. In some examples, turbo lag may occur as more boost is
desired, wherein the compressor of the exhaust-gas driven
turbocharger may not be able to meet the boost demand for a short
duration of time (e.g., less than 10 seconds). As such, the
electrically driveable compressor may only be activated during the
duration of time until the compressor of the exhaust-gas
turbocharger is up to speed and meeting the boost demand.
In this way, a compressor housing for a compressor of an
exhaust-gas turbocharger may comprise a plurality of outlets,
wherein the plurality of outlets comprises at least a first outlet
directing compressed air to an electrically driveable compressor
and a second outlet directing compressed air to a bypass. The
electrically driveable compressor may be activated during engine
conditions where the compressor of the exhaust-gas turbocharger may
not meet a boost demand when providing as much boost as possible.
The technical effect of arranging more than one outlet in the
compressor housing is to decrease packaging constraints, pressure
loss due to increased piping, and decrease manufacturing costs due
to less material being used.
An embodiment of a supercharged internal combustion engine
comprising an intake system shaped to supply charge air, an
exhaust-gas discharge system shaped to discharge exhaust gas, at
least one exhaust-gas turbocharger which comprises a turbine
arranged in the exhaust-gas discharge system and a compressor
arranged in the intake system, the compressor being equipped with
at least one impeller which is arranged on a rotatable shaft in a
compressor housing, and the compressor housing having a
charge-air-conducting flow duct which extends from an inlet region
of the compressor and extends downstream of the at least one
impeller, and an electrically driveable compressor, which is
arranged in the intake system downstream of the compressor of the
at least one exhaust-gas turbocharger, wherein the compressor
housing has at least two outlets, the charge-air-conducting flow
duct splitting downstream of the at least one impeller into at
least two arm-like duct branches, where a first arm-like duct is
fluidly coupled to a first outlet and a second arm-like duct is
fluidly coupled to a second outlet, the first outlet directing
compressed air from the compressor of the exhaust-gas turbocharger
to the electrically driveable compressor and the second outlet
bypassing the electrically driveable compressor. A first example of
the supercharged internal combustion engine further includes where
the charge-air-conducting flow duct splits downstream of the at
least one impeller into the first and second arm-like duct
branches, and where a junction is arranged between the first and
second arm-like duct branches. A second example of the supercharged
internal combustion engine, optionally including the first example,
further includes where a single shut-off element is arranged at the
junction and shaped to adjust compressed air flow to each of the
first and second arm-like duct branches. A third example of the
supercharged internal combustion engine, optionally including the
first and/or second examples, further includes where the first
arm-like duct branch comprises a first shut-off element and where
the second arm-like duct branch comprises a second shut-off
element. A fourth example of the supercharged internal combustion
engine, optionally including one or more of the first through third
examples, further includes where an intercooler arranged between
the compressor of the exhaust-gas turbocharger and the electrically
driveable compressor and a charge-air cooler arranged downstream of
each of the compressor of the exhaust-gas turbocharger and the
electrically driveable compressor.
An embodiment of a system comprising a compressor of an exhaust-gas
turbocharger comprising a compressor housing comprising a plurality
of outlets including at least a first outlet and a second outlet,
and where the first outlet is shaped to direct compressed air from
the compressor to an electrically driveable compressor and where
the second outlet is shaped to bypass compressed air away from the
electrically driveable compressor. A first example of the system
further includes where a controller with computer-readable
instructions stored on non-transitory memory thereof that when
executed enable the controller to adjust a shut-off element shaped
to adjust compressed air flow to the first outlet to increase
compressed air flow to the electrically driveable compressor in
response to an amount of boost provided by the compressor of the
exhaust-gas turbocharger being less than an amount of boost
desired. A second example of the system, optionally including the
first example, further includes where the controller further
comprises instructions enabling the controller to adjust the
shut-off element to decrease compressed air flow to the
electrically driveable compressor in response to the amount of
boost provided by the compressor of the exhaust-gas turbocharger
being equal to the amount of boost desired. A third example of the
system, optionally including the first and/or second examples,
further includes where the compressor of the exhaust-gas
turbocharger is larger than the electrically driveable compressor.
A fourth example of the system, optionally including one or more of
the first through third example, further includes where the first
outlet is separated from the second outlet, and where compressed
air in the first outlet does not mix with compressed air in the
second outlet. A fifth example of the system, optionally including
one or more of the first through fourth examples, further includes
where the compressor of the exhaust-gas turbocharger is arranged
along a single intake passage, and where the electrically driveable
compressor and the bypass are arranged downstream of the compressor
of the exhaust-gas turbocharger in the single intake passage. A
sixth example of the system, optionally including one or more of
the first through fifth examples, further includes where an
intercooler arranged between the compressor of the exhaust-gas
turbocharger and the electrically driveable compressor, and where
only compressed air flowing through the first outlet flows to the
intercooler. A seventh example of the system, optionally including
one or more of the first through sixth examples, further includes
where a charge-air cooler arranged in the single intake passage
downstream of each of the electrically driveable compressor and the
bypass, and where compressed air flowing out of each of the
electrically driveable compressor and the bypass flows to the
charge-air cooler.
A method comprising flowing charge-air to a compressor of an
exhaust-gas turbocharger to provide an amount of boost in response
to a boost demand, adjusting a shut-off element arranged in a
housing of the compressor to flow air compressed by the compressor
to a first outlet arranged in the housing in response to the amount
of boost being less than an amount of boost demanded, and where the
first outlet directs the compressed air to an electrically
driveable compressor, and adjusting the shut-off element arranged
in the housing of the compressor to flow air compressed by the
compressed to a second outlet arranged in the housing in response
to the amount of boost being equal to the amount of boost demanded,
and where the second outlet bypasses the electrically driveable
compressor. A first example of the method further includes where
adjusting the shut-off element to flow the compressed air to the
electrically driveable compressor further includes activating an
electric motor to spin the electrically driveable compressor. A
second example of the method, optionally including the first
example, further includes where the first outlet and the second
outlet are adjacent to each other. A third example of the method,
optionally including the first and/or second examples, further
includes where the housing comprises no additional inlets or other
outlets other than an exhaust-gas turbocharger inlet, the first
outlet, and the second outlet. A fourth example of the method,
optionally including one or more of the first through third
examples, further includes where compressed air flowing through the
first outlet does not flow into or mix with air in the second
outlet. A fifth example of the method, optionally including one or
more of the first through fourth examples, further includes where
flowing compressed air through the first outlet further includes
flowing the compressed air through an intercooler before flowing
the compressed air to the electrically driveable compressor. A
sixth example of the method, optionally including one or more of
the first through fifth examples, further includes where the
shut-off element is a pivotable flap.
Note that the example control and estimation routines included
herein can be used with various engine and/or vehicle system
configurations. The control methods and routines disclosed herein
may be stored as executable instructions in non-transitory memory
and may be carried out by the control system including the
controller in combination with the various sensors, actuators, and
other engine hardware. The specific routines described herein may
represent one or more of any number of processing strategies such
as event-driven, interrupt-driven, multi-tasking, multi-threading,
and the like. As such, various actions, operations, and/or
functions illustrated may be performed in the sequence illustrated,
in parallel, or in some cases omitted. Likewise, the order of
processing is not necessarily required to achieve the features and
advantages of the example embodiments described herein, but is
provided for ease of illustration and description. One or more of
the illustrated actions, operations and/or functions may be
repeatedly performed depending on the particular strategy being
used. Further, the described actions, operations and/or functions
may graphically represent code to be programmed into non-transitory
memory of the computer readable storage medium in the engine
control system, where the described actions are carried out by
executing the instructions in a system including the various engine
hardware components in combination with the electronic
controller.
It will be appreciated that the configurations and routines
disclosed herein are exemplary in nature, and that these specific
embodiments are not to be considered in a limiting sense, because
numerous variations are possible. For example, the above technology
can be applied to V-6, I-4, I-6, V-12, opposed 4, and other engine
types. The subject matter of the present disclosure includes all
novel and non-obvious combinations and sub-combinations of the
various systems and configurations, and other features, functions,
and/or properties disclosed herein.
As used herein, the term "approximately" is construed to mean plus
or minus five percent of the range unless otherwise specified.
The following claims particularly point out certain combinations
and sub-combinations regarded as novel and non-obvious. These
claims may refer to "an" element or "a first" element or the
equivalent thereof. Such claims should be understood to include
incorporation of one or more such elements, neither requiring nor
excluding two or more such elements. Other combinations and
sub-combinations of the disclosed features, functions, elements,
and/or properties may be claimed through amendment of the present
claims or through presentation of new claims in this or a related
application. Such claims, whether broader, narrower, equal, or
different in scope to the original claims, also are regarded as
included within the subject matter of the present disclosure.
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